JSFiddle - React, Tailwind, and code Playground

HTML

<div></div>

JavaScript

var userName = 'me';

var txt = '{"authenticationToken": 1, "authenticated": 2, "authenticationTokenExpiry": 3, "sessionTimeoutMinutes": 4, "userName": "' + userName + '"}';

var obj = $.parseJSON(txt);

$('div').text(JSON.stringify(obj));